Laminate boards of this type are prior known, having been used for instance in shipbuilding industry as insulating walls of various spaces.
Sandwich elements of mineral wool have been utilized to some extent in building industry. However, so far long elements have not been available, neither as roof or floor elements, nor as wall elements.
The idea of rotating cut laminates 90.degree. and of reassembling them in the turned position, thus providing a laminate board having fibres orientated perpendicularly to the plane of the board, is prior known. Such a laminate board has excellent resistance properties and is able to transmit shearing forces between its surface planes.
Finished sandwich elements of mineral wool with the fibres orientated perpendicularly to the surface plane of the element would be usable as roof, floor and wall elements, thus simplifying construction operations noticeably.